Purpose: :
Document clinical features, histopathologic and immunohistochemicalresults in a population of 14 young cats with neovascular proliferativevitreoretinopathy.

Methods: :
Cases diagnosed as neovascular vitreoretinopathy were selectedfrom a total of 7007 feline submissions from COPLOW. Informationon breed, age, gender, laterality and clinical features wererecorded. Slides were reviewed to describe the morphologic characteristics.Immunohistochemistry included GFAP, Factor VIII, Collagen IV,Laminin, SMA, and CD68 were performed on those globes availablefor further sectioning

Results: :
. Most cats presented at less than 1 year of age, with 8 of14 of the study population less than 6 months old. Two Persiancats were represented, two domestic medium hair and the remainderdomestic short hair. Among these breeds, 8 were female and 6were male. The most common clinical sign was glaucoma. Histopathology:Retinal detachments were noted in 11/14 eyes. The retina wasentirely avascular in one case, and 80-90% avascular in theremaining 13 cases. The course of retinal vessels traveled axiallywithin the vitreous towards the lens in all cases. The consistencyof the vitreous tended to be liquid. Iridal fibrovascular membraneswere found in all 14 cases. Anterior uveal inflammation wasnoted in 12/14 cases.Immunohistochemical findings included anintense GFAP staining pattern throughout the retina. CD68 andFactor VIII confirmed that blood vessels extended into the vitreousbut not the peripheral retina. Laminin and collagen IV demonstratedthat the neovascular proliferation was confined to within theexpanded inner limiting membrane and SMA demonstrated contractilespindle cells in the neovascular membrane.

Conclusions: :
Feline neovascular vitreoretinopathy is a vasoproliferativedisorder with similarities to ROP. Retinal detachments leadto neovascular glaucoma in young cats.